The shootout (sorry, Computer Language Benchmarks Game) recently updated
to GHC 6.12.1, and many of the results got worse. Isaac Gouy has added
the +RTS -qg flag to partially fix it, but that turns off the parallel
GC completely and we know that in most cases better results can be had
by leaving it on. We really need to tune the flags for these benchmarks
properly.
http://shootout.alioth.debian.org/u64q/haskell.php
It may be that we have to back off to +RTS -N3 in some cases to avoid
the last-core problem (http://hackage.haskell.org/trac/ghc/ticket/3553),
at least until 6.12.2.
Any volunteers with a quad-core to take a look at these programs and
optimise them for 6.12.1?
Cheers,
Simon